diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index 7ce092ab0f057d6aff3aa1b2a73818d594df32ce..50b61a92b08dd6a2e1548a7fd70d6a189d135797 100644
--- a/block/blk-sysfs.c
+++ b/block/blk-sysfs.c
@@ -938,6 +938,12 @@ int blk_register_queue(struct gendisk *disk)
 			return ret;
 		}
 	}
+
+	/*
+	 * Set the flag at last, so that block devcie can't be opened
+	 * before it's registration is done.
+	 */
+	disk->flags |= GENHD_FL_UP;
 	ret = 0;
 unlock:
 	mutex_unlock(&q->sysfs_lock);
diff --git a/block/genhd.c b/block/genhd.c
index 82c5b6e0afdbfa452b24bdaf72d421d44c18a028..94b0fe34a755f77016fd7eb34a876e45bffb3294 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -696,8 +696,6 @@ static void __device_add_disk(struct device *parent, struct gendisk *disk,
 	WARN_ON(!disk->minors &&
 		!(disk->flags & (GENHD_FL_EXT_DEVT | GENHD_FL_HIDDEN)));
 
-	disk->flags |= GENHD_FL_UP;
-
 	retval = blk_alloc_devt(&disk->part0, &devt);
 	if (retval) {
 		WARN_ON(1);